package com.sunyw.xyz.utils;

import javax.servlet.http.HttpServletRequest;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.Objects;

/**
 * Ip工具类
 */
public class IpUtils {

    /**
     * 获取请求的ip地址
     *
     * @param request http
     * @return String
     */
    public static String getIpAddr(HttpServletRequest request) {
        String ipAddress = request.getHeader ("x-forwarded-for");
        if (ipAddress == null || ipAddress.length () == 0 || "unknown".equalsIgnoreCase (ipAddress)) {
            ipAddress = request.getHeader ("Proxy-Client-IP");
        }
        if (ipAddress == null || ipAddress.length () == 0 || "unknown".equalsIgnoreCase (ipAddress)) {
            ipAddress = request.getHeader ("WL-Proxy-Client-IP");
        }
        if (ipAddress == null || ipAddress.length () == 0 || "unknown".equalsIgnoreCase (ipAddress)) {
            ipAddress = request.getRemoteAddr ();
            if (ipAddress.equals ("127.0.0.1") || ipAddress.equals ("0:0:0:0:0:0:0:1")) {
                //根据网卡取本机配置的IP
                InetAddress inet = null;
                try {
                    inet = InetAddress.getLocalHost ();
                } catch (UnknownHostException e) {
                    e.printStackTrace ();
                }
                ipAddress = Objects.requireNonNull (inet).getHostAddress ();
            }
        }
        //对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
        if (ipAddress != null && ipAddress.length () > 15) { //"***.***.***.***".length() = 15
            if (!(ipAddress.indexOf (",") <= 0)) {
                ipAddress = ipAddress.substring (0, ipAddress.indexOf (","));
            }
        }
        return ipAddress;
    }
}
